Spiral stairway



FIG. 1 is a top plan view of a spiral stairway showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a bottom plan view thereof; and

FIG. 4 is a perspective view thereof, taken from the upper front side of said stairway. 

The ornamental design for a spiral stairway, substantially as shown. 